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31.
Seasonal patterns of dehydrins and 70-kDa heat-shock proteins in bark tissues of eight species of woody plants 总被引:6,自引:0,他引:6
Michael Wisniewski Timothy J. Close Timothy Artlip Rajeev Arora 《Physiologia plantarum》1996,96(3):496-505
Although considerable effort has been directed at identifying and understanding the function and regulation of stress-induced proteins in herbaceous plants, reports concerning woody plants are limited. Studies with herbaceous crops have revealed similarities in the types of proteins that accumulate in response to a wide array of abiotic stresses and hormonal cues such as the accumulation of abscisic acid. Many of the identified proteins appear to be related to dehydrins (the D-11 subgroup of late-embryogenesis-abundant proteins). The objective of the present study was to determine if seasonal induction of dehydrins is a common feature in woody plants and to see if seasonal patterns existed for other stress-induced proteins. Bark tissues from eight species of woody plants were collected monthly for a period of 1.5 years. The species included: peach (Prunus persica) cv. Loring; apple (Malus domestica) cv. Golden Delicious; thornless blackberry (Rubus sp.) cv. Chester; hybrid poplar (Populus nigra); weeping willow (Salix babylonica); flowering dogwood (Cornus florida); sassafras (Sassafras albidum); and black locust (Robinia pseudo-acacia). Immunoblots of bark proteins were probed with a polyclonal antibody recognizing a conserved region of dehydrin proteins, and monoclonal antibodies directed against members of the HS70 family of heat-shock proteins. Some proteins, immunologically related to dehydrins, appeared to be constitutive; however, distinct seasonal patterns associated with winter acclimation were also observed in all species. The molecular masses of these proteins varied widely, although similarities were observed in related species (willow and poplar). Identification of proteins using the monoclonal antibodies (HSP70, HSC70, BiP) was more definitive because of their inherent specificity, but seasonal patterns were more variable among the eight species examined. This study represents only a precursory examination of several proteins reported to be stress related in herbaceous plants, but the results indicate that these proteins are also common to woody plants and that further research to characterize their regulation and function in relation to stress adaptation and the perennial life cycle of woody plants is warranted. 相似文献
32.
Knigge T Mann N Parveen Z Perry C Gernhöfer M Triebskorn R Köhler HR Connock M 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2002,131(3):259-269
Amongst animals, several hydrogen peroxide-generating oxidases are apparently restricted to molluscs. One of these, D-mannitol oxidase, is concentrated in the alimentary system, where it is associated with its own subcellular membrane system of unique tubular morphology, most likely representing a structural modification of the ER. These structures can be purified by subcellular fractionation and have been termed 'mannosomes'. Little is known about the functions of mannitol oxidase or of mannosomes, but the previously reported molluscicide-induced increase in mannosomes implies their involvement in a general stress reaction. In this study, we examined the effects of heavy metal stress in the terrestrial gastropod Arion lusitanicus. The activity of mannitol oxidase and mannosome abundance were monitored, together with metal effects on heat-shock protein level, and these parameters were compared to heavy metal accumulation in the digestive gland. We found that mannitol oxidase is inhibited by heavy metals more than other oxidases. On the other hand, hsp70 levels and mannosomal protein were increased with enhanced heavy metal stress, the latter indicating a probable increase in the number of mannosome organelles. Thus, stress protein (hsp70) and mannosomal protein were positively correlated with heavy metal accumulation, whereas the enzyme activity showed a negative correlation with increasing heavy metal content of the slugs. 相似文献
33.
Thaddeus S. Nowak Jr. Ursula Bond Milton J. Schlesinger 《Journal of neurochemistry》1990,54(2):451-458
A number of studies have demonstrated increased synthesis of heat shock proteins in brain following hyperthermia or transient ischemia. In the present experiments we have characterized the time course of heat shock RNA induction in gerbil brain after ischemia, and in several mouse tissues after hyperthermia, using probes for RNAs of the 70-kilodalton heat shock protein (hsp70) family, as well as ubiquitin. A synthetic oligonucleotide selective for inducible hsp70 sequences proved to be the most sensitive indicator of the stress response whereas a related rat cDNA detected both induced RNAs and constitutively expressed sequences that were not strongly inducible in brain. Considerable polymorphism of ubiquitin sequences was evident in the outbred mouse and gerbil strains used in these studies when probed with a chicken ubiquitin cDNA. Brief hyperthermic exposure resulted in striking induction of hsp70 and several-fold increases in ubiquitin RNAs in mouse liver and kidney peaking 3 h after return to room temperature. The oligonucleotide selective for hsp70 showed equivalent induction in brain that was more rapid and transient than observed in liver, whereas minimal induction was seen with the ubiquitin and hsp70-related cDNA probes. Transient ischemia resulted in 5- to 10-fold increases in hsp70 sequences in gerbil brain which peaked at 6 h recirculation and remained above control levels at 24 h, whereas a modest 70% increase in ubiquitin sequences was noted at 6 h. These results demonstrate significant temporal and quantitative differences in heat shock RNA expression between brain and other tissues following hyperthermia in vivo, and indicate that hsp70 provides a more sensitive index of the stress response in brain than does ubiquitin after both hyperthermia and ischemia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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36.
Wu X Zhao X Baylor L Kaushal S Eisenberg E Greene LE 《The Journal of cell biology》2001,155(2):291-300
During clathrin-mediated endocytosis, clathrin-coated pits invaginate to form clathrin-coated vesicles (CVs). Since clathrin-coated pits are planar structures, whereas CVs are spherical, there must be a structural rearrangement of clathrin as invagination occurs. This could occur through simple addition of clathrin triskelions to the edges of growing clathrin-coated pits with very little exchange occurring between clathrin in the pits and free clathrin in the cytosol, or it could occur through large scale exchange of free and bound clathrin. In the present study, we investigated this question by studying clathrin exchange both in vitro and in vivo. We found that in vitro clathrin in CVs and clathrin baskets do not exchange with free clathrin even in the presence of Hsc70 and ATP where partial uncoating occurs. However, surprisingly FRAP studies on clathrin-coated pits labeled with green fluorescent protein-clathrin light chains in HeLa cells show that even when endocytosis is blocked by expression of a dynamin mutant or depletion of cholesterol from the membrane, replacement of photobleached clathrin in coated pits on the membrane occurs at almost the same rate and magnitude as when endocytosis is occurring. Furthermore, very little of this replacement is due to dissolution of old pits and reformation of new ones; rather, it is caused by a rapid ATP-dependent exchange of clathrin in the pits with free clathrin in the cytosol. On the other hand, consistent with the in vitro data both potassium depletion and hypertonic sucrose, which have been reported to transform clathrin-coated pits into clathrin cages just below the surface of the plasma membrane, not only block endocytosis but also block exchange of clathrin. Taken together, these data show that ATP-dependent exchange of free and bound clathrin is a fundamental property of clathrin-coated pits, but not clathrin baskets, and may be involved in a structural rearrangement of clathrin as clathrin-coated pits invaginate. 相似文献
37.
Hadley KC Borrelli MJ Lepock JR McLaurin J Croul SE Guha A Chakrabartty A 《Cell stress & chaperones》2011,16(5):549-561
The inability of cells to maintain protein folding homeostasis is implicated in the development of neurodegenerative diseases,
malignant transformation, and aging. We find that multiphoton fluorescence imaging of 1-anilinonaphthalene-8-sulfonate (ANS)
can be used to assess cellular responses to protein misfolding stresses. ANS is relatively nontoxic and enters live cells
and cells or tissues fixed in formalin. In an animal model of Alzheimer’s disease, ANS fluorescence imaging of brain tissue
sections reveals the binding of ANS to fibrillar deposits of amyloid peptide (Aβ) in amyloid plaques and in cerebrovascular
amyloid. ANS imaging also highlights non-amyloid deposits of glial fibrillary acidic protein in brain tumors. Cultured cells
under normal growth conditions possess a number of ANS-binding structures. High levels of ANS fluorescence are associated
with the endoplasmic reticulum (ER), Golgi, and lysosomes—regions of protein folding and degradation. Nuclei are virtually
devoid of ANS binding sites. Additional ANS binding is triggered by hyperthermia, thermal lesioning, proteasome inhibition,
and induction of ER stress. We also use multiphoton imaging of ANS binding to follow the in vivo recovery of cells from protein-damaging
insults over time. We find that ANS fluorescence tracks with the binding of the molecular chaperone Hsp70 in compartments
where Hsp70 is present. ANS highlights the sensitivity of specific cellular targets, including the nucleus and particularly
the nucleolus, to thermal stress and proteasome inhibition. Multiphoton imaging of ANS binding should be a useful probe for
monitoring protein misfolding stress in cells. 相似文献
38.
大鼠液压冲击脑损伤热休克蛋白70基因表达的研究 总被引:3,自引:0,他引:3
张永亮 《中国应用生理学杂志》2000,16(2):104-107
目的:观察大鼠侧位液压冲击脑损伤时HSP70的表达分布特点及时序性变化。方法:雄性SD大鼠,给以0.2MPa液压冲击,造成脑损伤,应用免疫组织化学技术观察冲击后不同时间HSP70在脑组织内的表达特点。结果:冲击侧大脑皮层和脑干SHP70阳性神经辊冲击后2h和4h出现,7并逐渐增强直至12h;冲击后4h,冲击侧海马HSP70免疫阳性细胞开始出现,4 ̄12h,海马HSP70免疫阳性细胞数无明显改变。结 相似文献
39.
《Bioorganic & medicinal chemistry letters》2014,24(6):1523-1527
The non-receptor tyrosine kinase Syk (spleen tyrosine kinase) is a pharmaceutical relevant target because its over-activation is observed in several autoimmune diseases, allergy, and asthma. Here we report the identification of two novel inhibitors of Syk by high-throughput docking into a rare C-helix-out conformation published recently. Interestingly, both compounds are slightly more active on ZAP70 (Zeta-chain-associated protein kinase 70), which is the kinase closest to Syk in the phylogenetic tree of human kinases. Taken together, the docking pose and experimental results suggest that the higher affinity of the inhibitors for ZAP70 than Syk originates from a more populated C-helix-out conformation in ZAP70. The latter observation is congruent with the 100-fold lower intrinsic activity of ZAP70 than Syk, as the C-helix-out conformation is inactive. The pharmacophore features of DFG-in, C-helix-out compounds are analyzed in relation to DFG-out inhibitors. 相似文献
40.
Irene Konstantopoulou Christos A. Ouzounis Elena Drosopoulou Minas Yiangou Paschalis Sideras Chris Sander Zacharias G. Scouras 《Journal of molecular evolution》1995,41(4):414-420
A clone isolated from a Drosophila auraria heat-shock cDNA library presents two long, antiparallel, coupled (LAC) open reading frames (ORFs). One strand ORF is 1,929 nucleotides long and exhibits great identity (87.5% at the nucleotide level and 94% at the amino acid level) with the hsp70 gene copies of D. melanogaster, while the second strand ORF, in antiparallel in-frame register arrangement, is 1,839 nucleotides long and exhibits 32% identity with a putative, recently identified, NAD+-dependent glutamate dehydrogenase (NAD+-GDH). The overlap of the two ORFs is 1,824 nucleotides long. Computational analysis shows that this LAC ORF arrangement is conserved in other hsp70 loci in a wide range of organisms, raising questions about possible evolutionary benefits of such a peculiar genomic organization.Correspondence to: Z.G. Scouras 相似文献